Photo credit: Google
Polypodium interjectum Photo: Bill Johncocks
Preliminary studies on the diversity of the leaf-blade hair and stomata density in the Polypodium vulgare L. complex in Poland. In: E. Szczêniak, E. Gola (eds), Genus Polypodium L. in Poland.
by Gola E.M., Szczêniak E. (2012)
Edyta M. GOLA , Ewa SZCZÊNIAK – University of Wroclaw
in Polish Botanical Society, Wroclaw, p. 39-46
http://www.zbiosr.uni.wroc.pl/sites/default/files/003_1.pdf
ABSTRACT:
Polypodium vulgare complex in Central Europe consists of three taxa differing in the ploidy level, i.e. P. cambricum (2n), P. vulgare (4n) and P. interjectum (6n).
In Poland, only two latter species have been noted, as well as the hybrid between them, P. ×mantoniae (5n). These ferns are morphologically similar and thus their unequivocal identification is based on the measurement of the nuclear DNA content or chromosome counting.
An indirect tool for the taxon identification is the annulus structure, namely the number of indurated and basal cells. Here, we present an additional micromorphological feature, which is the presence of hairs at the leaf-blade surface. This feature has not been given in the manuals but it may possibly be useful in a taxon recognition. Further analyses and confirmation of the taxonomic value of this feature are however necessary due to limited material studied.
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Stomata and hairs were scattered on the entire abaxial leaf surface; they were absent only directly above the veins and at the leaf margins. The stomata size was related to the ploidy level, with the biggest guard cells in the hexaploid P. interjectum (stomata measurements in specimens studied are presented in Szczêniak et al. mscr), resulting in the lowest frequency of stomata in this taxon, opposite to their dense packing in P. vulgare, characterized by the smallest guard cells (Fig. 1D-F; Table 1).
The hybrid presented intermediate values to its parental species. Since the frequency of stomata remains inversely proportional to their sizes (Kott, Britton 1982; Kessler et al. 2007; Gabriel y Galán et al. 2010), density of stomata in the field of vision can indirectly suggest, which ploidy level occurs in a given specimen.
However, exhaustive studies on different ferns have shown that the stomata density can be much more variable within the species than between different taxa (Kessler et al. 2007; Gabriel y Galán et al. 2010), and also our preliminary results seem to confirm a variation of stomata packing in Polypodium taxa (Table 1), thus this feature requires careful evaluation.
PLANT STOMATA ENCYCLOPEDIA 